JP2005243430A - Planar light source device and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively mix different color lights from LEDs. <P>SOLUTION: Each of dichroic mirrors 126a, b reflects the light advancing along from a red LED 125a or a green LED 125c to the light incident plate 122a to the light incident plate 122a of a light guide plate 122. A part of the dichroic mirrors 126a, b is arranged between the light incident plate 122a and the blue LED 125b. The dichroic mirrors 126a, b transmit blue light. Thereby, three color lights of RGB can be mixed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a planar light source device and a display device, and more particularly to a planar light source device and a display device suitable for a liquid crystal display device using a light emitting diode (LED) as a light source.

  As an image display device for personal computers and other various monitors, or as a display screen of a mobile phone or a television receiver, there has been a remarkable spread of liquid crystal display devices. The liquid crystal display device typically includes a liquid crystal display panel and a backlight unit disposed on the back surface thereof. The liquid crystal display panel displays an image by controlling the transmitted light. The backlight unit typically includes a light source and a plurality of optical members for effectively emitting light from the light source to the liquid crystal display panel. As a light source of the backlight unit, a cold cathode tube and a light emitting diode (LED) are known.

  Unlike cold-cathode tubes, LEDs do not use mercury and are therefore increasingly used as light sources for backlight units. When an LED is used as a light source, a plurality of LED chips that emit different colors may be used in addition to an example in which a pseudo white LED is used. Typically, LED chips that emit light of three colors of red (R), green (G), and blue (B) are prepared, and the desired emission color is adjusted by adjusting the emission intensity of each color. A light source device having the same can be obtained.

  Since the LED chip is a point light source and a highly directional light source, when using LEDs that emit light of different colors, the light from each LED is mixed to obtain light of a desired color. It is necessary to do. Several means are known as means for mixing light from LEDs. One typical method utilizes a light guide plate. Light entering the light guide plate from the LED chips of each color propagates through the light guide plate while diffusing, and the light of each color is mixed.

  For example, Patent Document 1 discloses a technique in which LED lamps are arranged on both sides of opposing side surfaces of a light guide plate and light from the LED lamps is mixed. Each of the three colors of LEDs is a single color LED lamp 3 (R, G, B), and the arrangement of the two short sides of the light guide plate of the single color LED lamp facing each other is at least two colors of the same color. Since the LED surface light source device is arranged so as not to be troublesome, a complicated LED chip selection process when a white LED lamp in which three primary color LED chips are sealed in one case is formed in advance. Is unnecessary.

JP 2002-157909 A

  One requirement for display devices is a reduction in size. In particular, it is required to reduce the thickness or to reduce the area of the frame region that is the peripheral portion of the display device. The narrow frame design can reduce the size of the display device and increase the display area. As the display panel becomes larger and the required luminance increases, the power or size of the LED increases. Therefore, the design for miniaturization is important simultaneously with the design of the color mixture of light. For example, the configuration of Patent Document 1 has a narrow frame design because the LEDs are arranged on both sides of the light guide plate for color mixing of the light from the LEDs regardless of the size of the backlight unit that has the necessary light amount. There is a problem in terms. Alternatively, heat generation increases as the luminance of the LED increases, so this must be taken into consideration.

  The present invention has been made against the background described above, and a first object of the present invention is a planar light source device capable of mixing colors from different light sources and miniaturizing the device, and a display device using the same. Is to provide. Another object is to suppress a decrease in usability of the apparatus due to heat generation of the light source.

  According to a first aspect of the present invention, there is provided a planar light source device that emits planar light, the light guide plate that guides and diffuses incident light, the light source plate that is disposed opposite the incident surface of the light guide plate, and a first color. A first point light source (e.g., LED 125b in FIG. 3) that emits light of a second color, and a second light source that is disposed to face the incident surface and emits light of a second color different from the first color. A point light source (for example, LED 125a in FIG. 3) and a mirror (for example, FIG. 3) having a reflection surface that reflects light included in the second color light traveling along the incident surface toward the incident surface. 3 dichroic mirror 126a). This makes it possible to effectively mix different colors of light from the light source.

  It is preferable that the reflection surface selectively reflects light having a predetermined wavelength included in the light of the second color and transmits light of other wavelengths. Furthermore, at least a part of the reflective surface is disposed between the first point light source and the incident surface, and the reflective surface is directed from the first point light source toward the incident surface. It is preferable to transmit light of the color.

  A third point light source that is disposed opposite to the incident surface of the light guide plate and emits light of a third color different from the first and second colors, and the third point light source that travels along the incident surface. It is preferable to include a second mirror having a second reflecting surface that reflects light included in the color light toward the incident surface.

  The reflective surface selectively reflects light having a predetermined wavelength included in the light of the second color, and the second reflective surface selects light of a predetermined wavelength included in the light of the third color. It is preferable that the light be reflected. Further, at least a part of the reflecting surface is disposed between the first point light source and the incident surface, and the first color light traveling from the first point light source toward the incident surface is emitted. Transmitting, and at least a part of the second reflecting surface is disposed between the first point light source and the incident surface, and the first point light source is directed to the incident surface from the first point light source. It is preferable to transmit color light.

  It is preferable that the mirror and the second mirror have a plate shape, and the first point light source is disposed in a space formed between the mirror and the second mirror. Alternatively, it is preferable that a portion of the incident surface facing the first light source and a portion facing the mirror are roughened.

  A second aspect of the present invention is a display device having a planar light source device that emits planar light and a display panel that displays an image by controlling the amount of light from the planar light source device. The planar light source device includes a light guide plate that guides and diffuses incident light, a first point light source that is disposed opposite to the incident surface of the light guide plate and emits light of a first color, and the incident light source device. A second point light source disposed opposite to the surface and emitting light of a second color different from the first color, and light included in the light of the second color traveling along the incident surface And a mirror having a reflecting surface that reflects toward the incident surface. This makes it possible to effectively mix different colors of light from the light source.

  According to a third aspect of the present invention, there is provided a planar light source device that emits planar light, a frame, a light guide plate that is disposed in the frame and guides and diffuses incident light, and an incident surface of the light guide plate. Oppositely disposed in the frame and having a light source that emits light, and a heat shielding member disposed between the light source and the outer surface of the frame. Thereby, it is possible to suppress the heat of the light source from propagating to the outer surface of the frame and improve usability.

  It is preferable that the light source is disposed between the incident surface and the side wall of the frame, and the heat shield member is disposed between the light source and the inner surface of the side wall.

  A fourth aspect of the present invention is a display device having a planar light source device that emits planar light and a display panel that displays an image by controlling the amount of light from the planar light source device. The planar light source device includes a frame, a light guide plate that is disposed in the frame and guides and diffuses incident light, and a light source that is disposed in the frame so as to face the incident surface of the light guide plate and emits light. And a heat shield member disposed between the light source and the outer surface of the frame. Thereby, it is possible to improve the usability by suppressing the heat of the light source from propagating to the outer surface of the frame.

  According to one aspect of the present invention, it is possible to provide a planar light source device capable of mixing light from different light sources and miniaturizing the device, and a display device using the planar light source device.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description is to describe the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. Moreover, those skilled in the art can easily change, add, and convert each element of the following embodiments within the scope of the present invention. In addition, in each drawing, the same code | symbol is attached | subjected to the same element and the duplication description is abbreviate | omitted as needed for clarification of description.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid crystal display module which is an example of the display device of the present invention. In FIG. 1, 110 is a liquid crystal display panel which is an example of a display panel, and 120 is a backlight unit which is an example of a planar light source device. The liquid crystal display panel 110 is driven by a driving circuit (not shown), and can display an image by controlling transmission of light from the backlight unit 120.

  The liquid crystal display panel 110 has a display area composed of a plurality of pixels and a peripheral area formed around the display area. Each pixel in the display area of the liquid crystal display panel 110 performs RGB color display. In a monochrome display, a monotone display changing between white and black is performed. An active matrix type liquid crystal display panel has an array substrate on which switch elements such as TFTs (Thin Film Transistors) are formed on an array, and a counter substrate disposed to face the array substrate.

  As the liquid crystal display panel 110, in addition to the above active matrix type, a simple matrix type having no switching elements is known. Other types of liquid crystal display panels include TN (Twisted Nematic) type liquid crystal display panels, STN (Super Twisted Nematic) type liquid crystal display panels, and IPS (In Plane) in which pixel electrodes and common electrodes are formed on the same substrate. Switching) type liquid crystal display panels are known. The present invention is applicable to various types of liquid crystal display panels as described above.

  The backlight unit 120 includes an optical film 121 such as a prism sheet or a diffusion sheet, a light guide plate 122, a reflection sheet 123, a frame 124, a light emitting diode (LED) 125 as an example of a point light source, a dichroic mirror 126, and An LED circuit board 127 is provided. As illustrated in FIG. 1, the optical film 121, the light guide plate 122, and the reflection sheet 123 are stacked in this order from the display surface side. Light from the LED 125 enters the light guide plate 122. Light emitted from the upper surface of the light guide plate 122 enters the liquid crystal display panel 110 via the optical film 121.

  Each component of the backlight unit 120 will be described. The optical film 121 collects or diffuses light and adjusts the luminance within the display surface. The light guide plate 122 guides and diffuses the light from the LED 125 to emit planar light. The light guide plate 122 can be formed of a resin such as acrylic. The light guide plate 122 faces the LED 125 and is a light incident surface 122a on which light from the LED 125 is incident. The light guide plate 122 is an upper surface of the light guide plate 122. The light output surface 122b emits light toward the liquid crystal display panel 110. The back surface 122c of the light-guide plate facing 122b is provided.

  Typically, a dot pattern formed by dot printing or processing is formed on the back surface 122c of the light guide plate. Light from the LED 125 enters the light guide plate 122 from the light incident surface 122a and travels through the light guide plate 122 while repeating reflection. Part of the traveling light is emitted from the upper surface 122b of the light guide plate 122 to the liquid crystal display panel 110 side, whereby the light from the LED 125 can be irradiated to the liquid crystal display panel 110 as planar light.

  The reflection sheet 123 is disposed on the back surface 122c side of the light guide plate 122, and reflects the light incident from the light guide plate 122 to the display surface side. A part of the light incident on many embosses formed on the surface of the back surface 122c of the light guide plate 122 is reflected and a part of the light is transmitted. The reflection sheet 123 reflects the light emitted from the back surface 122 c to the light guide plate 122.

  The frame 124 accommodates components of the backlight unit 120 such as the optical film 121, the light guide plate 122, the reflection sheet 123, the LED 125, the dichroic mirror 126, and the LED circuit board 127. The frame 124 can typically be formed of an organic resin such as polycarbonate. The inner surface of the frame 124 is a white reflective layer, and the light from the LED 125 can be reflected toward the light guide plate 122.

  The LED 125 as a point light source is arranged in a position facing the light incident surface 122 a of the light guide plate 122 in the frame 124. In the frame 124, a plurality of LEDs 125 are arranged along the light incident surface 122a. In particular, the backlight unit 120 of this embodiment includes three colors of LEDs 125a, b, and c of R (Red), B (Blue), and G (Green). Although not shown, a plurality of LEDs are arranged for the three colors of LEDs 125a, b, and c. The dichroic mirror 126 will be described later with reference to FIGS. The LED circuit board 127 arranged in the frame 124 supplies current to the LED 125 and controls the light emission luminance of the LED 125 by changing the amount of supplied current.

  FIG. 2 is a perspective view showing a partial configuration of the backlight unit 120. An LED mirror unit 201 includes a plurality of LEDs 125 and a dichroic mirror 126. The LED mirror unit 201 is disposed between the light incident surface 122 a of the light guide plate 122 and the side wall 124 a of the frame 124. Although not shown, the backlight unit 120 includes a plurality of LED mirror units 201 arranged along the light incident surface 122 a of the light guide plate 122.

  FIG. 3 is a top view showing the configuration of the LED mirror unit 201. In this embodiment, the LED mirror unit 201 includes three LEDs 125a, b, c and two dichroic mirrors 126a, b disposed between the LEDs 125. In this example, the LED 125a is a red LED that emits red light, the LED 125b is a blue LED that emits blue light, and the LED 125c is a green LED that emits green light.

  The dichroic mirror 126a disposed between the red LED 125a and the blue LED 125b includes a reflection surface 211a that reflects light having a predetermined wavelength in a wavelength range emitted by the red LED 125a and transmits other light. The dichroic mirror 126b disposed between the green LED 125c and the blue LED 125b includes a reflection surface 211b that reflects light having a predetermined wavelength in the wavelength range emitted by the green LED 125c and transmits other light.

  Light from the red LED 125a travels along the light incident surface 122a, and light having a predetermined wavelength is reflected toward the light incident surface 122a by the reflective surface 211a. Light of other wavelengths passes through the reflecting surface 211a and the dichroic mirror 126a. Light from the green LED 125c travels along the light incident surface 122a, and light having a predetermined wavelength is reflected by the reflecting surface 211b toward the light incident surface 122a. Light of other wavelengths passes through the reflecting surface 211b and the dichroic mirror 126b.

  In this embodiment, the dichroic mirror 126 is formed by applying a coating (reflection surface) to a glass plate that is a plate-like member. Each of the two dichroic mirrors 126a and 126b reflects the light traveling along the light incident surface 122a from the red LED 125a or the green LED 125c toward the light incident surface 122a, so that the reflective surfaces 211a and b are LEDs 125a and b. It is arranged so as to have a predetermined angle with the optical path of the light from. As the reflection wavelength of the dichroic mirror 126, an appropriate wavelength and wavelength width are selected from the viewpoint of display color quality.

  Part of the dichroic mirrors 126a and 126b and the reflecting surfaces 211a and 211b are disposed between the light incident surface 122a and the blue LED 125b. However, since the dichroic mirrors 126a and 126b transmit blue light, light emitted from the blue LED 125b can be guided into the light guide plate 122 without loss. By using the dichroic mirror 126 in the above-described arrangement, the light paths of the light of each color can be incident on the light guide plate 122 with respect to each color of red, blue, and green from each LED 125 at a distant position. As a result, light from the plurality of LEDs 125 having high directivity can be effectively diffused and mixed in the light guide plate 122.

  The light from the red LED 125a or the green LED 125c is selectively reflected by the dichroic mirrors 126a and 126b. As a result, light of a desired color can be selectively incident on the light guide plate 122, so that the color of the planar light and the display quality of the liquid crystal display module 100 can be improved. On the other hand, since the blue LED 125b has lower light emission efficiency than other LEDs, the luminance can be efficiently increased by transmitting light from the blue LED 125b. For example, the color of the blue LED 125b can be improved by selectively using LED elements.

  In order to mix light of each color efficiently, the optical axes of red and green light reflected by the dichroic mirrors 126a and 126b and the optical axis of blue light transmitted through the dichroic mirrors 126a and 126b intersect each other. In particular, it is preferable to reflect and transmit light so that these optical axes are concentrated at almost one point. Therefore, the reflection surfaces of the dichroic mirrors 126a and 126b and the angle of incident light from the LEDs 125a and c are set so as to satisfy the above conditions.

  For this reason, in this embodiment, the substantially rectangular plate-like dichroic mirrors 126a and 126b are arranged so that the surfaces thereof have a predetermined inclination angle with respect to the light incident surface 122a. The distance between the light incident surface 122a side ends of the plate-like dichroic mirrors 126a, 126b is smaller than the distance between the frame side wall side ends on the opposite side. In the example of FIG. 3, the light incident surface 122a side end is in contact.

  Further, the blue LED 125b is placed at a position sandwiched between the plate-like dichroic mirrors 126a and 126b, and is disposed in a space defined by the dichroic mirrors 126a and 126b. Since the blue LED 125b can be disposed close to the light incident surface 122a of the light guide plate 122, it is possible to contribute to downsizing of the backlight unit (narrow frame of the display device). Moreover, since at least a part of the blue LED 125b and the plate-like dichroic mirrors 126a, b are arranged so as to overlap the light incident surface 122a, the optical axes of the RGB three-color light can be brought closer to each other. The three lights can be mixed efficiently.

  In addition, it is preferable that a portion where each light is incident on the light incident surface 122 a is roughened in order to promote diffusion in the light guide plate 122. Further, it is preferable that a portion other than the portion where the light from the LED mirror unit 201 is directly incident on the light incident surface 122a is not roughened. As shown in FIG. 3, the portion facing the blue LED 125b and the portion facing the reflecting surfaces 211a, b are roughened, and the other portions are not roughened. Thus, the light leaking from the LED mirror unit 201 and reflected in the frame 124 can be efficiently incident into the light guide plate 122. These points are the same in the following embodiments.

Second embodiment.
FIG. 4 is a plan view showing a schematic configuration of the LED mirror units 410 and 420 according to the present embodiment. The LED mirror unit 410 shown in FIG. 4A includes two dichroic mirrors 411a and 411b formed by coating a bulk-like transparent member. Other components are the same as those of the LED mirror unit 201 shown in FIG.

  The dichroic mirror 411a, b includes a triangular prism having two substantially perpendicular side surfaces and adjacent surfaces of the two side surfaces, and the reflecting surfaces 421a, b are formed by coating the adjacent surfaces. Yes. The reflective surface 421 selectively reflects the light from the LED 125 as in the first embodiment. The dichroic mirror 411a is disposed between the red LED 125a and the blue LED 125b, reflects the predetermined wavelength light included in the red light traveling along the light incident surface 122a from the red LED 125a toward the light incident surface 122a, and the other Transmits light of wavelength. The dichroic mirror 411b is disposed between the green LED 125c and the blue LED 125b, reflects the predetermined wavelength light included in the green light traveling along the light incident surface 122a from the green LED 125c toward the light incident surface 122a, and the other Transmits light of wavelength.

  The dichroic mirrors 411a and 411b are arranged so that the side surfaces are in contact with each other, and the blue LED 125b is arranged between the dichroic mirrors 411a and 411b and the frame side wall 124a. The reflecting surfaces 421a and b of the dichroic mirrors 411a and 411b are disposed between the blue LED 125b and the light incident surface 122a, but transmit blue light, so that light from the blue LED 125b is incident on the light incident surface 122a. There is no hindrance.

  The angle of the reflecting surface is substantially the same as in the first embodiment. In order to mix light of each color efficiently, the optical axes of red and green light reflected by the dichroic mirrors 411a and 411b and the optical axis of blue light transmitted through the dichroic mirrors 411a and 411b intersect each other. In particular, it is preferable to reflect and transmit light so that these optical axes are concentrated at almost one point. This also applies to the LED mirror unit 420. Note that the dichroic mirrors 411a and 411b can be integrally formed.

  The LED mirror unit 420 shown in FIG. 4B includes dichroic mirrors 451a and 451b having substantially rectangular plates. The dichroic mirror 451a disposed adjacent to the red LED 125a and disposed between the red LED 125a and the blue LED 125b includes a reflection surface 461a. The reflection surface 461a reflects light having a predetermined wavelength in the wavelength range emitted by the green LED 125c. Transmits light. The dichroic mirror 451b disposed adjacent to the green LED 125c and disposed between the green LED 125c and the blue LED 125b includes a reflective surface 461b, and the reflective surface 461b reflects light having a predetermined wavelength in the wavelength range emitted by the red LED 125a. Transmits light.

  The light from the red LED 125a travels along the light incident surface 122a and passes through the dichroic mirror 451a. Of the transmitted light, light having a predetermined wavelength is reflected by the reflecting surface 461b toward the light incident surface 122a. Light of other wavelengths passes through the reflecting surface 461b. The light from the green LED 125c travels along the light incident surface 122a and passes through the dichroic mirror 451b. Of the transmitted light, light having a predetermined wavelength is reflected by the reflecting surface 461a toward the light incident surface 122a. Light of other wavelengths passes through the reflecting surface 461a.

  In this embodiment, the dichroic mirrors 451a and 451b are arranged such that the reflecting surfaces 461a and b have a predetermined inclination angle with respect to the light incident surface 122a. The distance between the light incident surface 122a side ends of the plate-like dichroic mirrors 451a and 451b is larger than the distance between the frame side wall side ends on the opposite side. In the example of FIG. 4B, the frame side wall 124a side end is in contact.

  The blue LED 125b is placed at a position sandwiched between the plate-like dichroic mirrors 451a and 451b and the frame side wall 124a. The blue LED 125b and the reflecting surfaces 461a and b are arranged so that at least a part of the reflecting surface 461a and b overlaps the light incident surface 122a, but the reflecting surfaces 461a and b transmit the blue light from the blue LED 125b. Since the dichroic mirror 451 and the LEDs are in the above arrangement, the LEDs can be arranged closer to each other along the light incident surface 122a.

Third embodiment.
FIG. 5 shows a partial configuration of the backlight unit 510 in this embodiment. The backlight unit 510 of this embodiment includes a heat shield member 511 between the LED 125 and a part of the outer surface of the frame. The heat shielding member 511 suppresses heat from the LED 125 from being transmitted to a part of the outer surface of the frame, and reduces the difficulty of holding the backlight unit 510 or a display device using the same. it can.

  Components other than the heat shielding member 511 have been described in the first embodiment, and details are omitted. In FIG. 5, the ends of the dichroic mirrors 126a and 126b on the light incident surface 122a side are separated. The dichroic mirrors 126a and 126b are arranged so that the blue light from the blue LED 125b does not enter the reflecting surfaces 211a and 211b of the dichroic mirrors 126a and 126b.

  As the heat shield member 511, for example, a nonwoven fabric made of microfibers having a fiber diameter of 1 to 4 micrometers and short fibers having a fiber diameter of 20 to 30 micrometers can be used. The heat shielding member 511 is disposed on the inner surface of the frame side wall 124a, and in particular, is disposed on the inner surface side of the side wall 124a facing the light incident surface 122a of the light guide plate. By disposing the heat shield member 511 between the LED 125 and the side wall facing the LED 125, the temperature increase of the outer surface of the side wall 124a can be suppressed. Thus, the user can easily handle the display device by holding the side wall of the frame.

  The present invention can be applied to a light source device other than the backlight unit of the display device. The mirror that reflects the light from the LED is preferably a dichroic mirror, but an ordinary total reflection mirror can be used by changing the arrangement of the mirror and the LED. The present invention is not limited to the liquid crystal display device, and can be applied to other types of display devices.

  The LEDs can be arranged along two or more side surfaces of the light guide plate. In addition, it is preferable to use RGB three-color LEDs, but it is also possible to construct an LED mirror unit using two LEDs that emit light of different colors. It is also possible to arrange the LED mirror unit of the present invention on the side surface of the light guide plate that does not directly irradiate the liquid crystal display panel.

  The heat shielding member is not limited to a backlight unit using an LED, but can also be applied to a backlight unit using another type of light source such as a cold cathode tube. Further, due to the arrangement of the heat shielding member, an appropriate place can be selected by design depending on the structure of the backlight unit or the display device.

It is sectional drawing which shows schematic structure of the liquid crystal display module in 1st Embodiment. It is a top view which shows schematic structure of the liquid crystal display module in 1st Embodiment. It is a top view which shows schematic structure of the LED mirror unit in 1st Embodiment. It is a top view which shows schematic structure of the LED mirror unit in 2nd Embodiment. It is a top view which shows a partial structure of the backlight unit in 3rd Embodiment.

Explanation of symbols

100 liquid crystal display module, 110 liquid crystal display panel,
120 backlight unit, 121 optical film,
122 light guide plate, 122a light incident surface, 123 reflection sheet,
124 frame, 124a frame side wall, 125 LED,
126 Dichroic mirror, 127 LED circuit board,
201 LED mirror unit, 211 reflecting surface,
410 LED mirror unit, 411 LED mirror unit,
420 LED mirror unit, 421 reflecting surface,
451 dichroic mirror, 461 reflecting surface,
510 backlight unit, 511 heat shield member,

Claims (12)

A planar light source device that emits planar light,
A light guide plate that guides and diffuses incident light;
A first point light source disposed opposite to the incident surface of the light guide plate and emitting light of a first color;
A second point light source disposed opposite to the incident surface and emitting light of a second color different from the first color;
A mirror having a reflective surface that reflects the light included in the second color light traveling along the incident surface toward the incident surface;
A planar light source device.   The planar light source device according to claim 1, wherein the reflection surface selectively reflects light of a predetermined wavelength included in the light of the second color and transmits light of other wavelengths. At least a part of the reflecting surface is disposed between the first point light source and the incident surface,
The reflective surface transmits the first color light from the first point light source toward the incident surface.
The planar light source device according to claim 2. A third point light source that is disposed opposite to the incident surface of the light guide plate and emits light of a third color different from the first and second colors; and the third point light source that travels along the incident surface. A second mirror having a second reflecting surface that reflects light included in the color light toward the incident surface;
The planar light source device according to claim 1, comprising: The reflective surface selectively reflects light having a predetermined wavelength included in the light of the second color,
The second reflecting surface selectively reflects light having a predetermined wavelength included in the light of the third color;
The planar light source device according to claim 4. At least a part of the reflection surface is disposed between the first point light source and the incident surface, and transmits light of the first color from the first point light source toward the incident surface. ,
At least a part of the second reflecting surface is disposed between the first point light source and the incident surface, and the light of the first color traveling from the first point light source toward the incident surface. Transparent,
The planar light source device according to claim 5. The mirror and the second mirror are plate-shaped,
The first point light source is disposed in a space formed between the mirror and the second mirror.
The planar light source device according to claim 4.   2. The surface light source device according to claim 1, wherein a portion of the incident surface facing the first light source and a portion facing the mirror are roughened. A planar light source device that emits planar light, and a display device that displays an image by controlling the amount of light from the planar light source device, the planar light source device,
A light guide plate that guides and diffuses incident light;
A first point light source disposed opposite to the incident surface of the light guide plate and emitting light of a first color;
A second point light source disposed opposite to the incident surface and emitting light of a second color different from the first color;
A mirror having a reflective surface that reflects the light included in the second color light traveling along the incident surface toward the incident surface;
A display device. A planar light source device that emits planar light,
Frame,
A light guide plate disposed in the frame for guiding and diffusing incident light;
A light source disposed in the frame facing the incident surface of the light guide plate and emitting light;
A heat shield disposed between the light source and the outer surface of the frame;
A planar light source device. The light source is disposed between the entrance surface and a side wall of the frame;
The heat shield member is disposed between the light source and the inner surface of the side wall.
The planar light source device according to claim 10. A planar light source device that emits planar light, and a display device that displays an image by controlling the amount of light from the planar light source device, the planar light source device,
Frame,
A light guide plate disposed in the frame for guiding and diffusing incident light;
A light source disposed in the frame facing the incident surface of the light guide plate and emitting light;
A heat shield disposed between the light source and the outer surface of the frame;
A display device.

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